With the cause of her daughter’s death still a mystery, a Paso Robles woman once charged with murder will be out of jail this spring, a judge has ruled.

Erin Christine Martin, 45, maintained her innocence Monday, when she was sentenced for felony child endangerment. But even if her 3-month-old died as a result of an illness — not blunt force trauma, as one medical expert initially suggested — Martin is still culpable, a judge said, because she was drunk when her infant died.

“It’s troubling to me that you still have not come to terms with the part you played in her death,” Superior Court Judge Jacquelyn Duffy told Martin.

Martin received a six-year sentence for the neglect charge. But with time served and credit for good behavior, she has finished that term. Martin, who has been in jail since 2010, will have a remaining 72 days to serve on a yearlong sentence she received for a probation violation.

Martin called 911 on June 16, 2010, saying her daughter, Grace Martin, was unresponsive and not breathing. When police arrived, Erin Martin told them the baby had not been breathing for 30 minutes. A blood test revealed that the child’s mother had a blood alcohol content of 0.23 percent.

Grace Martin died two days later. The initial autopsy concluded that the infant had died as a result of blunt force trauma to the abdomen. But two other medical experts contradicted that report, complicating the case.

The baby had previously spent four weeks at a hospital in Los Angeles, suffering from a variety of ailments, including pneumonia, whooping cough and a respiratory virus infection, according to court records. At one point during that hospitalization, the baby’s respiratory system was paralyzed, and she was placed on the drug methadone. Erin Martin was at her baby’s bedside during the entire hospital stay.

“Everything that could have gone wrong with this child did,” defense attorney Ken Cirisan said in court.

In court, Martin said she could have proven her innocence.

“I’ve always been prepared to go to trial,” she said.

With conflicting medical reports, Deputy District Attorney Jesse Marino said the cause of death could not be readily determined. And children with Grace Martin’s illnesses do have a higher mortality rate, he added.

“It’s the most difficult case I’ve ever been involved with,” he said in court.

Still, Erin Martin’s actions on that day — being intoxicated and delaying her call to 911 — constituted neglect, he said.

“We felt like she was a person who’s been irresponsible in the past, and this was another example of her irresponsibility,” Marino told The Tribune during a previous hearing.

Martin’s history includes two convictions for alcohol-related offenses and a 2009 battery she committed on her ex-husband, Donald Martin.

When contacted by The Tribune, Donald Martin, who was not the father of Grace Martin, declined to comment. According to court records, he told the Probation Department that Erin Martin battered him in front of their two children, now ages 21 and 15.

“She hit me hard enough to knock me to the floor and loosen the crown on my tooth,” he said.

Donald Martin said the incident was the last straw in “a cycle of physical, psychological, emotional abuse” that dated back to 2004.

In that case, the Probation Department noted Erin Martin’s history of alcoholism.“During the interview process, she reported being an alcoholic and stated she consumed alcohol to deal with daily life stressors,” the probation report read. “Based on her prior record and statements, it appears that alcohol has played a significant role in regard to her behavior and decision-making.”

Grace Martin’s birth certificate does not list a father. Erin Martin told the Probation Department she met the father — whom she described as a drug addict — at a local bar.

Martin told the Probation Department she had been sober for a long time prior to the day her child died. That day, she drank because she was stressed over money, she said, and then she and the infant fell asleep together. When she woke up, she said, her baby was discolored.

“I did perform CPR,” she told the judge Monday.

When her baby was unresponsive, Martin said, she placed her on the bed beside her and called her roommate.

“I was in shock,” said Martin, a massage therapist who took college courses in early childhood development.

Even with a plea that reduced the severity of the charges, the Probation Department recommended the upper term — 10 years in prison — saying the case “exemplifies a mother’s neglect and inability to properly care for her infant daughter.”

Duffy, the judge, said the recommendation was too severe. She told Martin there were many factors in the child’s death but added, “You were one of those factors.”